CZ306454B6 - A catheter for inserting plastic stents - Google Patents

Abstract

The catheter consists of the sheath (2), in which there is located the shaft (5) with the olive (6). The shaft (5) is, at the proximal end, equipped with the helical element (4) which is fixed to this shaft (5) with one end and, with the opposite end, this helical element (4) is placed on and fitted into the piston (3) placed on the shaft (5). The piston (3) is designed for insertion into the sheath (2). The helical element (4) has mostly, along its length, different helix pitches and the shaft (5) is divided inside the piston (3) and its distal part (5b) is fixed to this piston (3). The shaft (5) is, at the distal end, provided with the stiffener (8) ending in the catheter hub (10) and, at the proximal end (5a), it is provided with the fixing ring (7) for securing the olive (6).

Description

Catheter for insertion of plastic stents

Field of technology

The invention relates to a catheter for the insertion of plastic stents, formed by a sheath, in which a shaft with an olive is placed, and used in particular in the indications biliary, transhepatic, TIPS and bronchial.

Prior art

Previously known catheters and introducers for placing stents in the human body are mostly used to insert metal stents, which are made of special shape memory alloys. These stents can be placed in a catheter or introducer indefinitely. Due to the physical properties of plastic stents, their permanent placement in the delivery device is not desirable. Plastic stents must therefore be placed in the delivery device before the actual operation. Concurrently used catheters and delivery devices that are designed to deliver metal stents cannot be used for plastic stents due to possible damage to the stents when compressed into the introducer. If the metal stents are placed incorrectly in the human body, the partially deployed stent can be recompressed, but this is difficult to do when inserting plastic stents because they are deformed.

According to US 2010/076402, a balloon catheter with a spring-loaded end part is known, and US 6,881,201 also discloses a balloon catheter whose end has a helical end and a guide wire provided with a thread at the end. These solutions are not suitable for the insertion of plastic stents and, in particular, do not solve the possibility of re-inserting the stents into the introducer and placing it and expanding it in the right place in the body cavity. This problem is not solved even by the document US 2009/247878 which discloses a spring-loaded probe for insertion into the human body.

It is therefore an object of the invention to provide a catheter which allows plastic stents to be inserted smoothly, eliminates their deformation when placed in the introducer, allows them to be pushed out safely, recompressed into the introducer and prevents the shaft or stents from breaking during catheter bends.

The essence of the invention

The object is achieved by an embodiment of a catheter according to the invention, the essence of which consists in that the shaft is provided at the proximal end with an inserted and fixed spiral member, which is usually attached to this shaft at one end and the opposite end is inserted into a piston mounted on the shaft. wherein the piston is arranged to slide into the sheath. This design allows for safe assembly, placement as well as possible recompression into the sheath and placement of the plastic stent at the desired location in the patient's body.

In a preferred embodiment, the helical member has a different pitch along its length.

The shaft is usually divided inside the plunger and its distal and proximal portions are attached to the plunger.

In order to easily determine the position of the shaft and if the shaft is inserted into the sheath when inserting stents, the piston is made of a color contrasting material.

In order to facilitate insertion, reinforcement and prevent unwanted bending, the shaft at the distal end is provided with a reinforcement, which is usually terminated by a holding member.

- 1 CZ 306454 B6

The olive is secured with a fixing ring located on the shaft.

Explanation of drawings

The catheter for inserting plastic stents according to the invention is schematically shown in the accompanying drawing, where Fig. 1 shows a catheter assembly, Fig. 2 shows the proximal end of this catheter with an olive, a spiral member and a plunger, and Fig. 3 shows a detail. design of a spiral part with different pitches.

Examples of embodiments of the invention

The catheter for introducing plastic stents is formed by a sheath 2, at one end of which a Y connector 9 is placed, attached to the sheath 2 by a cap nut 11. The connector 9 serves to attach a syringe for possible injection of X-ray contrast fluid. A shaft 5, made up of two parts, a proximal part 5a of smaller diameter and a distal part 5b of larger diameter, passes through the sheath 2, pushed into the piston 3, in which these parts 5a and 5b are connected and to which one end of the helical part 4 is also connected. of smaller pitch, also slid into the piston 3. The helical part 4 is also slid onto the proximal part 5a of the shaft 5, on which it is mounted. Behind the spiral part 4, the proximal part 5a is provided with a fixing ring 7 and an olive 6 is placed thereon. The piston 3 is slidable into the sheath 2 and the distal end 5b of the shaft 5 is provided with a stiffener 8 terminated by a catheter hub 10 for holding the distal end 5b of the shaft. 5.

The plastic stent is placed on the proximal part 5a of the shaft 5 and is compressed into the sheath 2 via the helical part 4. Subsequently, the sheath 2 is pushed into the patient's body cavity to the required place. After this insertion, the shaft 5 is held by the catheter with the hub 10, and when the sheath 2 is pulled back, the stents are released, which expands and presses against the wall of the body cavity. However, during insertion, the stent is first partially left inserted in the sheath 2, while being held by a helical member 4. This is done in the event that the stents are misplaced. If this occurs, the stent is back-compressed and slid back into the sheath 2 by means of the helical member 4, which is inserted into the correct place in the body cavity, where the stent is released again. The fixing ring 7 serves to securely hold the olive 6. The distal end 5b of the shaft 5 reinforced by the reinforcement 8 makes it easier to guide the shaft 5 when compressing the stents into the sheath 2, compressing the stents and releasing it. Catheter hub 10 allows comfortable attachment of the end of the shaft 5.

Claims (8)

PATENT CLAIMS A catheter for introducing plastic stents, formed by a sheath (2), in which a shaft (5) with an olive (6) is placed, characterized in that the shaft (5) is provided at the proximal end (5a) with an inserted spiral member (4). ), which is attached to this shaft (5) by at least one end. Catheter according to claim 1, characterized in that the helical part (4) is attached to the shaft (5) at one end and this helical part (4) is partially pushed into the piston (3) pushed onto the shaft (5) at the opposite end, wherein the piston (3) is arranged to slide into the sheath (2). Catheter according to claim 2, characterized in that the helical part (4) is attached to the piston (3). Catheter according to Claim 1, characterized in that the helical member (4) has a different pitch of the helix along its length. -2EN 306454 B6 Catheter according to claim 2, characterized in that the shaft (5) is divided inside the piston (3) and its distal part (5b) is attached to this piston (3). 5 Catheter according to claim 1, characterized in that the shaft (5) is provided with a stiffener (8) at the distal end. Catheter according to Claim 6, characterized in that the reinforcement (8) is provided at the end with a catheter hub (10). O Catheter according to claim 1, characterized in that the shaft (5) is provided at the proximal end (5a) with a fixing ring (7) for securing the olive (6).